The ratio between the number of molecules in 2 g of hydrogen and 32 g of oxygen is:
[Atomic mass: H=1, o=16]

1. 1:2

2. 1:0.01

3. 1:1

4. 0.01:1

One mole of sulphur dioxide represents which of the following?

P 22.4 litres at STP

Q 6.02 x 10²³ atoms

R 6.02 x 10²³ molecules

1. Only P

2. Only Q

3. Both P and Q

4. Both P and R

Assertion (A): The absolute scale of temperature is the Kelvin scale.

Reason (R): Kelvin scale starts from 0°C.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Assertion (A): Triatomic molecules consist of four atoms.

Reason (R): Monoatomic molecules contain only one atom.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.